Modern hearing assistance devices typically include digital electronics to enhance the wearer's experience. In the specific case of hearing aids, current designs employ digital signal processors rich in features. Their functionality is further benefited from communications, either from a remote source or from ear-to-ear for advanced processing. Thus, it is desirable to add wireless functionality to a hearing instrument to allow for functions such as ear to ear synchronization, remote control, programming and configuration, streaming audio, bi-directional audio, etc. Many of the functions in a hearing aid such as volume control, memory select, etc. are changed or modified on an intermittent basis. Further, the RF transceiver within the hearing aid consumes a significant amount of power for both transmission and reception of wireless signals. Because of the intermittent nature of many of the control functions in a hearing aid, it is desirable to build a communication system that uses as little power as necessary to communicate the information, either from a remote device or from one aid to another. Events including, but not limited to, volume control changes and variation in background noise happen intermittently and at irregular intervals and it is important that related information is shared and thus synchronized with both hearing instruments. Radio communications using frequencies above 200 MHz in a hearing instrument allow for far field electromagnetic transmissions. These frequencies can be used at close range such as ear to ear communication and longer range (for example, greater than 2 meters) for functions such as remote control, configuration and streaming audio. In the unlicensed ISM bands of 900 MHz and 2.4 GHz, there can be multiple competing radiating devices that can interfere with low power communications. The situation is made worse when the desired communications are intermittent and the interferers have high power and/or long duty cycles.
What is needed in the art is a system for low power communications in a hearing assistance device. The system should support intermittent communications for the hearing assistance device. It should be useable in environments with radio frequency interference.